An Introduction to Plant Based Diets

Hillary Wright, MS, RD
Senior Nutritionist
Dana Farber Cancer Institute

At first pass it may sound like vegetarianism, which itself can mean a few different things. The strictest form is a vegan diet, which only includes foods from plant sources, like fruits, vegetables, whole grains, soy foods, legumes, nuts and seeds. Many self-identified vegetarians are actually “lacto-ovo” vegetarians, meaning they eat plant foods, eggs, and dairy products, like milk, yogurt and cheese, but no animal flesh. There are also those who mainly consider themselves vegetarians but also eat seafood, some occasionally poultry, or maybe just avoid red meat. Despite the differences, what all have in common is a focus on getting most of their nutrients from plants. Two of the most recognized plant-based diets are the Mediterranean Diet and The DASH Diet (Dietary Approaches to Stop Hypertension). Both suggest significant increases in fruits and vegetables (targets are higher than those consumed by the average American), favor whole grains, and include plant proteins like nuts, seeds and legumes. Both suggest limitations on animal protein, with the Mediterranean Diet recommending seafood over poultry, and that red meat be consumed “sparingly.” Another less familiar but highly regarded plant-based diet in the nutrition science world is the OmniHeart diet. Backed by the National Institutes of Health, the OmniHeart Diet provides three different options for a heart-healthy plant-based diet that emphasize more carbohydrates, proteins or unsaturated fats, depending on one’s preferences. Like Mediterranean and DASH, all three OmniHeart patterns include a big push for more fruits and vegetables, and inclusion of plant proteins from nuts, seeds and legumes. It’s also worth noting that all these plant based plans allow dairy in moderation — all encouraging low or reduced-fat versions — and suggest limiting added sugars and refined carbohydrates.